Ok, this tutorial seems to be kind of messed up. It will work to take a custom TS3 hair useable in TSM, but not an EA hair. Also, any hair based on any TS3 file that is not included will fail. It must be a well made TS3 package that includes all the external files (meshes, Textures, etc....).

About the FNV64 vs FNV32. Almost all TSM/TS3 resourses use an FNV64 GUID (Global Unique Identifier). Some, very few, but still some use an FNV32. For your modding purposes, never use an FNV32. I've modded the crap out of this game and have never use the FNV32 button.

The buttons. (I'm about to explain stuff that the timid don't want to hear, you've been warned) FNV is the Fowlerâ€“Nollâ€“Vo is a non-cryptographic hash function created by Glenn Fowler. Basically you supply a string, and it gives you a unique ID based on that string. The string will always produce the same FNV hash, so without knowing the GUID you can supply an easily interpretable name and always get the same number. The 32 and 64 refer to the precision of the hash. A 32 FNV hash can produce a 32 bit hash, in TSM it's 0x00000000FB1EE897 for the string "GrimsFNVTest". A 64 FNV hash can produce a 64 bit hash (most common is TSM/TS3) which with the same string results in 0x97FBBE21CA372C37. Try it yourself, type this string in S3PE and click the buttons you'll get te same results. Change one letter, and you'll get something different. The main difference is, how likey is it that two strings could get the same hashed ID. A 32 bit ID is actually going to produce the same IDs for different strings something like a thousand times more than an 64 bit ID. It's exponential, and hexi based instead of deci based.

Long story short, always use FNV64 unless the file you're rewriting is a 32 file, as in the first eight bit are zero.

Next only ever hit one button to get an ID. If you hit FNV64 then FNV32 you've overwritten your FNV64. Only click FNV64. Trust me, never use the FNV32 button, always the 64. You have no need for the FNV32 button.

Do not EVER change the type, unless you know damn sure what you're doing. If we take this hair tut as an example, and it's discussed CASP file, the CASP is the type. If you change the CASP to another type it will not work. TSM/TS3 counts on knowing what each type means.

Really, to make a TS3 hair show in TSM takes almost nothing. This is a test I made. I downloaded the Seperoth hair from MTS. Put the package in my mods folder. Opened it. Selected the CASP and selected the GRID button. Clicked commit. Saved and closed the package. Here are my results (note the lack of steps):

The most recent one ;u;
EDIT:
That was a good hint actually, haha! Downloading an old (REALLY old lmao) version made grid available :D!!!

Though I'm at a loss why some hair shows up and other don't... I'm doing exacly the same things for them! (checking medievalprofession, dlothingcategories->profession, and in instance clicking FNV32, and checking compress and use resource name, as well as giving said resource name...) this is confusing and I'm a poor newbier

The most recent one ;u;
EDIT:
That was a good hint actually, haha! Downloading an old (REALLY old lmao) version made grid available :D!!!

Though I'm at a loss why some hair shows up and other don't... I'm doing exacly the same things for them! (checking medievalprofession, dlothingcategories->profession, and in instance clicking FNV32, and checking compress and use resource name, as well as giving said resource name...) this is confusing and I'm a poor newbier

All you should have to do is change the clothing category to true for professions.
Since the latest wrapper, more often than not, TS3 files already have all the heroes switched to true, I'd take a look just to make sure but you shouldn't have to touch anything in there.
You don't change the resource and you don't change the instance (and if you did it would be FNV64 not FNV32).

Just turn clothing category>profession to true if it's marked false
Check in medieval profession that the heroes are marked true (switch to false any you don't want it to appear on)
Click commit and save the package.
More often than not this is sufficient, (and if it isn't it's most likely something else in the casp that needs changed)

All you should have to do is change the clothing category to true for professions.
Since the latest wrapper, more often than not, TS3 files already have all the heroes switched to true, I'd take a look just to make sure but you shouldn't have to touch anything in there.
You don't change the resource and you don't change the instance (and if you did it would be FNV64 not FNV32).

Just turn clothing category>profession to true if it's marked false
Check in medieval profession that the heroes are marked true (switch to false any you don't want it to appear on)
Click commit and save the package.
More often than not this is sufficient.

Fiddling with that did the trick somehow! Thanks a lot, I really appreciate the help

Hi, it is a long time someone posted here I see. But I've god a question. (I didn't read all the seven pages so maybe someone asked it already, I'm an impatient girl :D).
Well I'm thinking of making a story with the sims 3 which will be around the medieval ages. Now I've looked everywhere for proper medieval clothes but most of the costum content just doesn't look right if you ask me. It doesn't fit in. So I looked for some conversions from the sims medieval. I've looked everywhere and eventually I found some clothes and stuff but the things I want in my game from tsm I couldn't find. So I thought: 'I'm going to convert them myself then.' Well that's harder then I thought. I'm really a Noob with converting and I've never done it before. So I looked for tutorials but I could only find this one. But this is from TS3 to TSM. And I want the other way around. Could someone make a tutorial for me? I would really appreciate it :D.
Thanks for reading.

I've not successfully been able to pull this off. The first hurdle is changing the CASP from Medieval Version 17 to TS3 version 12. There's not a tool to do it, so it would have to be done in hex. First change the version number. Then you need to remove BlendInfoMedievalElderIndex, BlendInfoMedievalTeenIndex, OutfitMaterial, MedievalUnknown, and MedievalProfession. After you've removed them you have to write in the new offset to the TGI. Then you would have to track down every file that the object used. You could use my cloner to get some of it, but the cloned objects rely on certain universal files (Skeletons, Texture Controllers, Patterns, etc...). If you got every file referenced, it may work. If you miss any you'll crash to desktop. Best I've gotten so far is the CASP showing up in Create a Sim, but the outfit doesn't show up on the sim. Just a floating head. I'll keep fiddling with it. Or if you think you're able to do what I've listed here I'd answer any more questions about it you might have.

I'm trying to convert some of Anubis360's hairstyles. I am STILL having trouble after following and re-reading the instructions in this thread. I've tried downloading an older version (the one ChickieTeeta had pointed out) but the grid button is still showing up grey. I'm sure I'm using the correct wrapper. I can't figure out what I'm doing wrong. (Also, I wish there was an updated tutorial so that people wouldn't have to go through multiple pages/threads to try and figure this out)

I'm working on the updated tutorial. Part of what I felt I needed to do was get the wrappers updated to use the latest version of S3PE. I had to figure out how to write a wrapper first. Now I've added the appropriate wrappers thanks to velocitygrass, I'll be writing a new tutorial, but it will be on the SimsWiki Medieval Modding page. This way it can be updated better, and kept clean. I'll try to get it up this weekend.

All you should have to do is change the clothing category to true for professions.
Since the latest wrapper, more often than not, TS3 files already have all the heroes switched to true, I'd take a look just to make sure but you shouldn't have to touch anything in there.
You don't change the resource and you don't change the instance (and if you did it would be FNV64 not FNV32).

Just turn clothing category>profession to true if it's marked false
Check in medieval profession that the heroes are marked true (switch to false any you don't want it to appear on)
Click commit and save the package.
More often than not this is sufficient, (and if it isn't it's most likely something else in the casp that needs changed)

Ok, this tutorial seems to be kind of messed up. It will work to take a custom TS3 hair useable in TSM, but not an EA hair. Also, any hair based on any TS3 file that is not included will fail. It must be a well made TS3 package that includes all the external files (meshes, Textures, etc....).

About the FNV64 vs FNV32. Almost all TSM/TS3 resourses use an FNV64 GUID (Global Unique Identifier). Some, very few, but still some use an FNV32. For your modding purposes, never use an FNV32. I've modded the crap out of this game and have never use the FNV32 button.

The buttons. (I'm about to explain stuff that the timid don't want to hear, you've been warned) FNV is the Fowlerâ€“Nollâ€“Vo is a non-cryptographic hash function created by Glenn Fowler. Basically you supply a string, and it gives you a unique ID based on that string. The string will always produce the same FNV hash, so without knowing the GUID you can supply an easily interpretable name and always get the same number. The 32 and 64 refer to the precision of the hash. A 32 FNV hash can produce a 32 bit hash, in TSM it's 0x00000000FB1EE897 for the string "GrimsFNVTest". A 64 FNV hash can produce a 64 bit hash (most common is TSM/TS3) which with the same string results in 0x97FBBE21CA372C37. Try it yourself, type this string in S3PE and click the buttons you'll get te same results. Change one letter, and you'll get something different. The main difference is, how likey is it that two strings could get the same hashed ID. A 32 bit ID is actually going to produce the same IDs for different strings something like a thousand times more than an 64 bit ID. It's exponential, and hexi based instead of deci based.

Long story short, always use FNV64 unless the file you're rewriting is a 32 file, as in the first eight bit are zero.

Next only ever hit one button to get an ID. If you hit FNV64 then FNV32 you've overwritten your FNV64. Only click FNV64. Trust me, never use the FNV32 button, always the 64. You have no need for the FNV32 button.

Do not EVER change the type, unless you know damn sure what you're doing. If we take this hair tut as an example, and it's discussed CASP file, the CASP is the type. If you change the CASP to another type it will not work. TSM/TS3 counts on knowing what each type means.

Really, to make a TS3 hair show in TSM takes almost nothing. This is a test I made. I downloaded the Seperoth hair from MTS. Put the package in my mods folder. Opened it. Selected the CASP and selected the GRID button. Clicked commit. Saved and closed the package. Here are my results (note the lack of steps):

I have done exactly what you've been saying. And the hair I am trying to convert is not showing up in game? What am I doing wrong?

i've got big problem with that hair i've done everything like in tutorial but there's a problem with that hair well there's also version for male it's works good

Excuse me, I don't know English very well, I speak Russian. "Google" helps me to translate .
Previously, I also faced a similar problem. And also the problem of change in eye color (see Attachment).
I solved these problems (not in all cases) by using the TS3 program "TSR Workshop".
I have changed patterns in the category "Texture"! "TS3" uses some patterns are not in "Medieval". But patterns can be imported from a good hairstyle.
Open TSR Workshop. Create New Project. New Import. Point your hairstyle file (in package or sims3pack format). (Not all custom hairstyles can be opened).
In "Texture" bookmark look at PATTERNS A, B, C and D (see my Attachment Screenshoot). They must be replaced.
Double-clicking on the pattern image. Import.
I joined all four high-quality patterns. Just in case.
And then File > Export > To Sims3Pack. Or as you wish. And further convert the hairstyle using Sim3Pe .
(But it's necessary to convert the file to Package format, I use S3PackageViewer for this).

I converted some of Rose' s TS3 hairtyles. Some the hairstyles have red texture in game. Some of them affect the eye texture. Also, many of them are bigger than the average TSM head, so when I choose those hairstyles, sims look as if they are bald and wearing wigs. Any idea how to fix it?

I converted some of Rose' s TS3 hairtyles. Some the hairstyles have red texture in game. Some of them affect the eye texture. Also, many of them are bigger than the average TSM head, so when I choose those hairstyles, sims look as if they are bald and wearing wigs. Any idea how to fix it?

The problem of influence on the eyes' texture really enrages me . I don't know how to solve it, but today (today only!) I've found one way, a fairly simple way. To wear lenses! We can use "Flajko's Pure Eyes For TSM", many thanks to ChickieTeeta (the lenses are here ), I made a post with screenshots how it looks (here).
Perhaps many people have guessed before this simple technique, but I guessed only today.